P2X7 receptor expression is required for microglial activation by amyloid-beta and P2X7 inhibition reduces amyloid plaques in Alzheimer’s disease transgenic mice (Sanz et al., 2009; Diaz-Hernandez et al., 2012; Ni et al., 2013). The gene discussed is P2RX7; the disease is early-onset autosomal dominant Alzheimer disease.